▎ 摘　　要

NOVELTY - Preparation of photochromic visualization biosensor involves preparing three-dimensional graphene-supported cobalt-nitrogen co-doped titanium dioxide nanocomposite and Prussian blue solution, making indium tin oxide electrodes with working areas such as module (A) and module (B), preparing Prussian blue thin film using electrodeposition method, modifying the three-dimensional graphene-supported cobalt-nitrogen co-doped titanium dioxide nanocomposite dispersion on the surface of the module (A) and module (B), drying, processing the module (B), modifying the surface of the three-dimensional graphene-supported cobalt-nitrogen co-doped titanium dioxide nanocomposite in the module (A), processing with chitosan, modifying ochratoxin A aptamer solution, incubating, washing with phosphate buffer solution, blocking unbound active sites with bovine serum albumin, washing with phosphate buffered solution and drying. USE - The method is useful for preparation of photochromic visualization biosensor, which is useful for detecting ochratoxin A (claimed). ADVANTAGE - The photochromic visualization biosensor detects ochratoxin A with high accuracy, does not contain complicated equipment, and can be identified by the naked eye. The three-dimensional graphene-supported cobalt-nitrogen co-doped titanium dioxide nanocomposite has excellent photoelectric activity and stability, and reduces the interference of various external and internal factors.